A lot of evidence in The Show and outside it indicates Dean was intentionally written as either bi or gay right from the beginning of the series. For example: https://sinnabonka.tumblr.com/post/636429205801959424/bidean-by-episode
Kripke wrote Sam as his self-insert, and Dean as an analogy of his older brother. Putting in gay 'jokes' and subtext could have been his way of making fun of his brother or men like Dean.
However, I've recently been thinking about how Dean is presented to the viewer compared to Sam. Dean is the only one presented in a way which invites sexual objectification of ogling in any way, e.g. in bed in a t-shirt and underwear at the beginning of 1x04 Phantom Traveler, or topless in bed at the beginning of 1x11 Scarecrow. Dean is presented as the one the viewer can find sexually attractive, whereas Sam is not. Sure, some people think he's good-looking, but he's always fully dressed and never presented sexually. Episode 4x17 It's a Terrible Life also makes an (insulting) parallel between Dean and a Ken Doll, dressing and grooming him exactly like a Ken Doll.
Dean being bi/gay from the beginning could well have been intentional, but something else came to me recently: Jensen auditioned for Sam, but got turned down and offered the role of Dean instead. I wonder whether this choice was part of a ploy to give both women AND men the good down-low tickle. He IS swoonworthy, and if Dean is both presented as possibly, subtly gay/bi in a way only the gays would get, AND portrayed by a man who belongs in a Greek heroic legend, the show can guarantee a large following of gay/bi men as well as straight and bi women.
Please don't misunderstand me: Jensen's performance and Dean's character are THEE reason I watch the show, and he's infinitely more than a pretty face. I'm also not implying he had any active part in said gaybaiting. He's THEE best thing that could have happened to the show, but I still wonder how much of a role his physical appearance had, and whether it was linked in any way to queerbaiting.
I'll draw no conclusions, but here's what I'm currently thinking.
